Prospective resources are used while planning exploration and prospecting activities.

Based on the corresponding certainty degree, oil and gas resources are divided into contingent resources (C3 category), localized forecast resources (D1 loc category) and forecast resources (D1 and D2 categories).

C3 category – contingent oil and gas resources developed for deep drilling of traps within an oil and gas bearing location, delineated using geological and geophysical research methods checked for this region, as well as untapped formations of explored fields, if their productivity was determined at other regional fields. The configuration, extension and mode of occurrence of an inferred deposit are generally identified on the basis of geological and geophysical research, while reservoir thickness and properties as well as oil or gas composition and properties are assumed similarly to the explored fields.

D1 loc category – localized forecast resources of traps discovered at the conclusion of exploratory geological and geophysical research, and located within the regions with a proven or possible oil & gas presence.

A quantitative assessment of localized forecast resources is conducted with regard to the density of D1 forecast resources and the specified area of a discovered site.

Localized forecast oil and gas resources are used when planning exploration activities on the traps preparation for prospecting drilling and development of C3 category in-place resources.

D1 category – forecast oil and gas resources of lithostratigraphic units, assessed within large regional structures with a proven commercial oil & gas presence.

A quantitative assessment of D1 forecast oil and gas resources is conducted at the conclusion of regional geological, geophysical and geochemical research and similarly to fields explored within the region under assessment.

D2 category – forecast oil and gas resources of lithostratigraphic units, assessed within large regional structures with commercial oil & gas presence not yet proven. The potential of oil and gas presence in these units is forecast on the basis of geological, geophysical and geochemical research data.

A quantitative assessment of forecast resources of this category is conducted using presumable parameters derived from general geological concepts and by analogy with other, more closely investigated regions containing explored oil and gas fields.